Perhaps you should try some spelling variations:
nhan khoa » nha khoa, khuan khoa, toan khoa
sach hoi » sach doi, sach moi, cach thoi
cuu cong » cua cong, thu cong, cac cong
cong hoc » dong hoc, cong hoa, cong coc
hoc nhan » hoc nhanh, nhoc nhan, hoc phan
khoa hoc » hoa hoc
lang tai » lang thai, tang tai, sang tai
hang tai » hang va, dung tai
so sach » so sanh, bo sach, co sach
hoi tap » hoi dap, hoc tap, hoi tai
hoc xa » hoc ma

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: so sach hoi tap, nghien cuu cong hoc nhan khoa hoc xa hoi va ((lang tai) or (hang tai))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach hoi tap, nghien cuu cong hoc nhan khoa hoc xa hoi va ((lang tai) OR (hang tai)).
• Adding a wildcard symbol may retrieve word variants: so sach hoi tap, nghien cuu cong hoc nhan khoa hoc xa hoi va ((lang tai) or (hang tai))*.